The present invention relates to a toilet tank outlet valve, particularly, a floatless outlet valve for use in both the drainage and the overflow in a toilet tank, which valve being operable in two stages and being easily removable for repair or for a displacement.
It has been found that the conventional outlet valve used in the cistern of a flush toilet consists of an outlet valve, an overflow tube and a control float. Since such an outlet valve lacks a water-saving mechanism, every time when the toilet is flushed, the duration in which the float-controlled valve is open is always the same; hence, no matter whether the toilet is used for evacuation of bowels or for urination, the amount of water that flows down the flush pipe will be the same, that is, water will continue to flow until the cistern is completely drained during one flush. Release of water in this way may sometimes be very wasteful.
Currently, a water-saving mechanism has been developed for use with a toilet tank to save water and already several kinds of commercial products therefor are available on the market. However, because of the complicated construction and high cost in the production of this water-saving mechanism as well as the need for an additional installation of parts or the replacement in whole of the set of inlet and outlet valves in the tank, it has been very inconvenient. Again, the valve adapted to cover the metallic valve seat in the conventional outlet valve is only a rubber valve sheet fixed to a metal sheet. After used for some time, such rubber valve may be worn out easily due to friction with the metal, or the valve port edge itself may be rust-eaten and thus become uneven. In this way, the valve will lose its seal, leading to leakage in the tank causing much waste of water. Although this can be remedied by replacing a new valve sheet for the worn-out one, the installation of a new valve sheet can be accomplished only with the help of tools; the requirement of different tools might present an inconvenience to a family in general. As for the rusting of the edge of the valve port, the only solution thereof may be to replace it with a new outlet pipe connection. Furthermore, in a conventional outlet valve, if the float bowl leaks or is punctured and thus becomes ineffective, or the over-flow pipe becomes rusted, it will be required that the complete set be removed and replaced by a new set. At the same time, the replacement work requires tools and this is also troublesome.
It is the purpose of this invention to ameliorate the afore-said disadvantages in the conventional outlet valve, and to provide a novel outlet valve for use with flushing toilets, which can deliver precise action and can easily be installed in a tank, and by which water saving can thus be effected.
Therefore, the principal object of this invention is to provide for use in tanks an outlet valve having the overflow pipe and valve seat formed integrally, wherein the outlet valve unit can be assembled merely by turning the unit in a positive or negative direction by a small degree without having to rely on any tools.
A further object of this invention is to provide for use in a toilet tank an outlet valve having no attachment whatsoever of a float and a float arm, and as such, the whole structure thereof being substantially compact and small in size, and being further space-saving when installed inside the tank.
A further object of this invention is to provide for use in a toilet tank an outlet valve which by the close association of the cup-like control member with the valve rod is capable of discharging water in the tank completely or partially in accordance with the need of the user so that water saving can be effected.
Another object of the invention is to provide for use in a toilet tank an outlet valve, the overflow tube thereof being open toward the water surface such that outside debris are prevented from falling from the above into the tube to cause blockage therein.
A still another object of the invention is to provide for use in a toilet tank an outlet valve, the expanded rubber valve member used therein being capable of keeping the valve seat always in the sealed condition so that any shortcoming in leakage due to imperfect sealing can thus be prevented.